Geologic Maps of the U.S. States
The first and only complete set of state geologic maps on the Web. To learn more about the geology of the 50 states, see the Regional Geology category.
About Online State Geologic Maps
Going online to see a geologic map of your state can be rewarding--or frustrating.
Going online to see a geologic map of your state can be rewarding--or frustrating.
Alabama
From the Geological Survey of Alabama, presented here with notes from your Guide.
From the Geological Survey of Alabama, presented here with notes from your Guide.
Alaska
A complicated map of this huge state, presented here at three sizes.
A complicated map of this huge state, presented here at three sizes.
Arizona
Excerpted from the USGS national map and presented here at two sizes.
Excerpted from the USGS national map and presented here at two sizes.
Arkansas
A gigantic U.S. Geological Survey map presented here at four different scales.
A gigantic U.S. Geological Survey map presented here at four different scales.
California
A classic U.S. Geological Survey map presented here in four different sizes.
A classic U.S. Geological Survey map presented here in four different sizes.
Colorado
Ogden Tweto's beautiful 1979 USGS map presented here at three different sizes.
Ogden Tweto's beautiful 1979 USGS map presented here at three different sizes.
Connecticut
A sketch map with explanation created by the State Geological and Natural History Survey.
A sketch map with explanation created by the State Geological and Natural History Survey.
Bedrock Map of Connecticut
The Talcott Mountain Science Center hosts this clickable map with USGS quads in full detail.
The Talcott Mountain Science Center hosts this clickable map with USGS quads in full detail.
Delaware
The generalized map by the Delaware Geological Survey, presented here at three sizes.
The generalized map by the Delaware Geological Survey, presented here at three sizes.
Florida
A Florida Department of Environmental Protection map presented here at two large sizes.
A Florida Department of Environmental Protection map presented here at two large sizes.
Georgia
Created from the USGS database and served here in four sizes.
Created from the USGS database and served here in four sizes.
Hawaii
The Aloha State presented here at three sizes.
The Aloha State presented here at three sizes.
Idaho
A simplified map of this large and rugged state from the state geological survey.
A simplified map of this large and rugged state from the state geological survey.
Illinois: Bedrock
Illinois' bedrock is almost totally hidden but the state geological survey has mapped it all.
Illinois' bedrock is almost totally hidden but the state geological survey has mapped it all.
Illinois: Quaternary Cover
Illinois is covered with recent glacial deposits, shown in this map from the state geological survey.
Illinois is covered with recent glacial deposits, shown in this map from the state geological survey.
Indiana: Bedrock
Click on the rock units for details in this Indiana Geological Survey map. Shockwave plug-in required.
Click on the rock units for details in this Indiana Geological Survey map. Shockwave plug-in required.
Indiana: Quaternary Cover
A clickable map from the Indiana Geological Survey shows the state's glacial deposits.
A clickable map from the Indiana Geological Survey shows the state's glacial deposits.
Iowa: Bedrock
A map from the Iowa Geological Survey Bureau shows the state's hidden side.
A map from the Iowa Geological Survey Bureau shows the state's hidden side.
Iowa: Quaternary Cover
An Iowa Geological Survey Bureau map with all the glacial details.
An Iowa Geological Survey Bureau map with all the glacial details.
Kansas
A Kansas Geological Survey map presented here at three sizes.
A Kansas Geological Survey map presented here at three sizes.
Kentucky
A Kentucky Geological Survey map presented here at two different sizes.
A Kentucky Geological Survey map presented here at two different sizes.
Louisiana
A simple map from the state geological survey.
A simple map from the state geological survey.
Maine: Bedrock
The hidden, ancient rocks of Maine mapped by the Maine Geological Survey.
The hidden, ancient rocks of Maine mapped by the Maine Geological Survey.
Maine: Quaternary Cover
Maine's extensive glacial deposits, from the Maine Geological Survey.
Maine's extensive glacial deposits, from the Maine Geological Survey.
Maryland
The 1968 state geological survey map presented here at three sizes.
The 1968 state geological survey map presented here at three sizes.
Massachusetts
A simplified bedrock map and simplified history of the Bay State.
A simplified bedrock map and simplified history of the Bay State.
Michigan: Bedrock
Two different state geological survey maps presented at several sizes.
Two different state geological survey maps presented at several sizes.
Mississippi
A generalized map courtesy of the Gulf of Mexico Program.
A generalized map courtesy of the Gulf of Mexico Program.
Missouri
A map by the Missouri Department of Natural Resources presented here at two sizes.
A map by the Missouri Department of Natural Resources presented here at two sizes.
Montana
The Big Sky State mapped by Montana State University and presented here at two sizes.
The Big Sky State mapped by Montana State University and presented here at two sizes.
Nebraska: Bedrock
Excerpted from the USGS national map and presented here at two sizes.
Excerpted from the USGS national map and presented here at two sizes.
Nevada
A USGS map of this geologist's paradise presented here at four sizes.
A USGS map of this geologist's paradise presented here at four sizes.
New Hampshire: Bedrock
The Granite State, presented here at four sizes.
The Granite State, presented here at four sizes.
New Jersey
From the state Geological Survey.
From the state Geological Survey.
New Mexico
Mapped by the state Bureau of Mines & Mineral Resources, presented here in two versions.
Mapped by the state Bureau of Mines & Mineral Resources, presented here in two versions.
New York
A large and informative state geological survey map, presented here at three sizes.
A large and informative state geological survey map, presented here at three sizes.
North Carolina
Presented here at two sizes.
Presented here at two sizes.
North Dakota: Bedrock
The state's hidden rocks beneath its glacial drift, presented here at three sizes.
The state's hidden rocks beneath its glacial drift, presented here at three sizes.
North Dakota: Surface Geology
Rocks and glacial sediments cover the state, shown at three sizes.
Rocks and glacial sediments cover the state, shown at three sizes.
Ohio: Bedrock
The Ohio Geological Survey calls this the Old State Bedrock Map but surely the rocks are the same today.
The Ohio Geological Survey calls this the Old State Bedrock Map but surely the rocks are the same today.
Ohio: Surface Geology
Glacial traces and sediments mapped by the Ohio Geological Survey.
Glacial traces and sediments mapped by the Ohio Geological Survey.
Oklahoma
From the Oklahoma Geological Survey.
From the Oklahoma Geological Survey.
Oregon
A classic USGS map presented here in three sizes.
A classic USGS map presented here in three sizes.
Pennsylvania
A 2000 state geologic survey map, presented here at three sizes.
A 2000 state geologic survey map, presented here at three sizes.
Rhode Island
A huge map from the Rhode Island State Geologist is presented here at three different scales.
A huge map from the Rhode Island State Geologist is presented here at three different scales.
South Carolina
A generalized map from the state Geological Survey.
A generalized map from the state Geological Survey.
South Dakota
From the South Dakota Geological Survey—click on an area to see the key.
From the South Dakota Geological Survey—click on an area to see the key.
Tennessee
Presented by the state Department of Environment and Conservation.
Presented by the state Department of Environment and Conservation.
Texas
A simplified map from the Texas Bureau of Economic Geology presented here at four sizes.
A simplified map from the Texas Bureau of Economic Geology presented here at four sizes.
Utah
The Beehive State, presented here at four scales.
The Beehive State, presented here at four scales.
Vermont: Bedrock
This map from the Vermont Geological Survey was issued in 1961.
This map from the Vermont Geological Survey was issued in 1961.
Virginia
Schematic map and a brief introduction to Virginia geology.
Schematic map and a brief introduction to Virginia geology.
Washington
A classic USGS map, presented here in four sizes.
A classic USGS map, presented here in four sizes.
West Virginia
A slightly small version from the West Virginia Geological and Economic Survey.
A slightly small version from the West Virginia Geological and Economic Survey.
Wisconsin: Bedrock
A small version from the University of Wisconsin Extension.
A small version from the University of Wisconsin Extension.
Wisconsin: Quaternary Cover
Glacial deposits of the state from the University of Wisconsin Extension.
Glacial deposits of the state from the University of Wisconsin Extension.
Wyoming
Excerpted from the USGS national map and shown at two sizes.
Excerpted from the USGS national map and shown at two sizes.